Training in Research on Addictions in Interdisciplinary NeuroAIDS (TRAIN) Interdisciplinary clinical research on the combined effects of substance abuse and HIV infection on brain structure and function is of considerable relevance to public health initiatives. However, there are presently very few laboratories conducting such research and no current training programs dedicated to preparing the next generation of investigators in clinical research at the intersection of addictions and neuroAIDS. Accordingly, we propose to establish a new Ruth L. Kirschstein National Research Service Award Institutional Training Grant (NRSA T32) entitled, Training in Research on Addictions in Interdisciplinary NeuroAIDS (TRAIN). The aim of TRAIN is to prepare a steady state of four pre-doctoral students and two post-doctoral fellows in clinical neuropsychology for multidisciplinary academic careers focused on the central nervous system (CNS) effects of substance abuse and HIV infection. We will recruit a highly qualified and culturally diverse cohort of trainees that demonstrate promise toward achieving productive academic careers. The TRAIN program will emphasize research training in three primary, interrelated CNS outcomes, which were selected because of their salience and public health relevance as clinical features of HIV-infected substance abusers: (1) neurocognitive impairment (e.g., decision-making, memory); (2) everyday functioning (e.g., medication adherence, vocational outcomes); and (3) structural and functional neuroimaging (e.g., diffusion tensor imaging). Students and fellows will be actively engaged in individualized, flexible career development plans that will include applied research training, didactics (e.g., formal class work and structured seminars), and targeted clinical experiences. An accomplished faculty with strong training interests and a long history of collaborative research will be available to mentor the trainees. The TRAIN faculty consists of 20 mentors across multiple academic disciplines that possess considerable expertise in neural injury, neuroimaging, neuropsychology, and everyday functioning in substance abuse and HIV infection. TRAIN will be led by Dr. Steven Paul Woods and Co-Directors, Drs. Igor Grant and Robert K. Heaton, who will oversee all of the training, scientific, and administrative aspects of the program, including a rigorous process of internal and external evaluation. The TRAIN program will be housed within the Department of Psychiatry at the University of California, San Diego, where it will benefit from a resource rich academic environment that includes a strong substance abuse and neuroAIDS research infrastructure, most notably the NIDA-funded Translational Methamphetamine AIDS Research Center (TMARC). In summary, TRAIN will bring together a bright and diverse cohort of pre- and post-doctoral trainees, an accomplished multidisciplinary team of mentors, an effective administrative structure, and broad array of academic resources to prepare the Nation's next generation of academics who will advance the science and practice of substance abuse and neuroAIDS.